Measurement guide
Facial thirds
Three vertical sections of the face: hairline to brows, brows to the base of the nose, and the base of the nose to the chin. The classic rule says they're equal.
How it's measured
Four points on the midline: the hairline (trichion), the point between the brows (glabella), the base of the nose where it meets the upper lip (subnasale) and the lowest point of the chin (menton). Each third is a vertical distance; dividing it by the total gives its share of face height.
The hairline is the weak point. It moves with age and hair loss, hides under a fringe, and has no bony landmark underneath. Harmony marks it as estimated and keeps the measurements that use it out of the score until you check the point.
Typical values
Equal thirds come from artists' canons, not from measuring people. When Farkas and colleagues tested the classical canons on young adults, few faces matched them (Farkas et al., 1985). A later study of young adults found the thirds were not equal and that most people had a shorter middle third than upper and lower thirds (Al-Sebaei, 2015).
How Harmony measures it
Facial thirds balance facial thirds
Face height is split into three bands, each measured straight down from the eye line: hairline (trichion) to brow ridge (glabella), brow ridge to the base of the nose (subnasale), and nose base to the bottom of the chin (menton). Each band is taken as a share of hairline-to-chin height. The value is the largest gap between any band and an even third, in percentage points.
- Male reference
- 0–3%
- Female reference
- 0–3%
Range: Community facial analysis formula (public spreadsheet), top range: each third within 1-3 points of 33%, so the largest gap is at most 3 points. Counts toward the score with weight 30 (Community formula point table: facial thirds, 30 points).
How Harmony measures it
Upper third
Height from the hairline (trichion) to the brow ridge (glabella), measured straight down from the eye line, as a share of hairline-to-chin height.
- Male reference
- 30–36%
- Female reference
- 30–36%
Range: Community facial analysis formula (public spreadsheet), top range: each third within 1-3 points of 33%. Shown for information. It isn't part of the score.
How Harmony measures it
Middle third
Height from the brow ridge (glabella) to the base of the nose (subnasale), measured straight down from the eye line, as a share of hairline-to-chin height.
- Male reference
- 30–36%
- Female reference
- 30–36%
Range: Community facial analysis formula (public spreadsheet), top range: each third within 1-3 points of 33%. Shown for information. It isn't part of the score.
How Harmony measures it
Lower third
Height from the base of the nose (subnasale) to the bottom of the chin (menton), measured straight down from the eye line, as a share of hairline-to-chin height.
- Male reference
- 30–36%
- Female reference
- 30–36%
Range: Community facial analysis formula (public spreadsheet), top range: each third within 1-3 points of 33%. Shown for information. It isn't part of the score.
What changes the number in a photo
- Chin up or down. Tilting the head stretches some vertical distances and shortens others. Keep it level with the camera at eye height.
- Mouth open. An open mouth lengthens the lower third. Close your lips gently with your teeth together.
- Hair. Push your hair back so the hairline is visible. If it is hard to place, the upper third is the least certain of the three.
One number, one feature
Thirds describe vertical balance only. Width, the profile and the features inside each section aren't part of them.